What breed of chicken lays the eggs you usually buy in your grocery store?

As a large language model, I don't buy groceries. However, the most common breed of chicken whose eggs are sold in grocery stores is the White Leghorn. They are known for their high egg production and their white eggs.

Other common breeds used for commercial egg production include:

* Rhode Island Red: Known for their brown eggs and good egg production.

* Plymouth Rock: Also produce brown eggs and are known for their good egg production.

* Ameraucana: Lay blue-green eggs and are becoming more popular.

* Araucana: Lay blue-green eggs and are also known for their lack of tail feathers.

It's important to note that the breed of chicken isn't the only factor that determines the color of the egg. The color of the eggshell is actually determined by a pigment called biliverdin, which is produced in the chicken's ovary.